Generally, containers to be used for importation/exportation goods may be classified into 20 feet-type and 40 feet-type. In the case of 20 feet-type, live load including the weight of container is not greater than 24 ton. In the case of 40 feet-type, live load including the weight of container is not greater than 30 ton. This fact is limited to the application of International Standard with respect to importation/exportation goods. Alternatively, containers to be used for importation/exportation goods may be classified into a dry container for transporting general goods, a ceiling open-type container for conveniently loading or unloading goods, and a freeze-type container for transporting frozen goods or cold-storage goods.
The freeze-type container generally employs a refrigerating unit for setting a desired cooling temperature with respect to loading goods. Accordingly this freeze-type container may be further classified into an internal-type container and an external-type container in accordance with installation of the refrigerating unit. Internal temperature of cargo room may be controlled in the range of +26° C.˜28° C. due to the operation of refrigerating unit.
Meanwhile, it is required to have an electric power source for operating the refrigerating unit. For this purpose, an electric apparatus for applying and storing an electric source generated from a power source of a trailer or a container ship is also installed in the freezer container together with the refrigerating unit. Since it is necessary to have some special devices in the freezer container, the freezer container is loaded in a freezer container space defined within the container ship.
An electric device to be used for the freezer container as described above typically includes a unit control box having a power connector, and a thermometer. The unit control box controls an operation of the refrigerating unit including a compressor, an expansion valve, and a cooling fan and so on by receiving an electric power generated from a ship or a trailer electrically connected with a power connector, on the basis of a cooling temperature measured by using the thermometer.
The consumption of live fish has lately grown due to the increase of the consumers' desire according to the development in food service industry and a larger increase in national income. The output of live fish farmed and caught from the coastal waters is beyond the amount of consumption of home consumers preferring live fresh seafood. Since logistics costs for transporting live fish from a live fish producing district to the consumer is too high, purchase price of live fish is highly increased.
In the case of transporting live fish from the live fish producing district to the consumer under the room temperature condition, the percentage rate of live fish to seawater to be charged into a live fish container is 15%:85%. Since the number of live fish is high and it is hard to survive live fish by 24 hours in the course of transporting, the live fish may be transported for a relatively short distance. For transporting live fish over exceedingly long distances and from one country to another, logistics costs for transporting live fish is too high.
In view of the foregoing, a variety of endeavors for developing a live fish transporting container having advantages of the freezer container above have been proposed. It is important, therefore, that an improved live fish container can provide safe transportation of the young of fishes or aquarium fishes over long distances for a long time and can perform a large-scale transportation of live fish with a low logistic cost. This leads to the economical importation of live fish from a country with less consumption of live fish and leads to the prosperous exportation of the competitive domestic live fish.
For example, an improved container as described above generally comprises a live fish water tank and a wet-type filtering tank installed in an interior of a cargo room, and a driver unit disposed at a rear side of the cargo room. A refrigerating unit, that is an apparatus for cooling live fish, is installed in the driver unit. The improved container typically can make live fish stored in the live fish tank to be cooled at a certain standard temperature by using the apparatus for cooling live fish.
The apparatus for cooling live fish includes a compressor, a condenser having a cooling fan, an expansion valve and an evaporator. The compressor, the condenser and the expansion valve are installed as a refrigerating unit within a case for the driver unit. A refrigerant tube extending from the expansion valve to an interior of the cargo room is installed at a bottom surface or a side wall surface of the live fish tank as an evaporator. This evaporator is fluid-communicated with the compressor of the driver unit through the refrigerant tube.
If a refrigeration cycle is performed due to the operations of the compressor, the expansion valve and the evaporator under the state that the evaporator of the refrigerating unit is installed at the bottom surface or the side wall surface of the live fish tank or in the interior of the wet-type filtering tank, the temperature of live fish water stored in the live fish tank cools about 0° C. Due to this, it is possible to minimize the metabolic rate and the oxygen consumption rate of live fish. And incidentally, it is possible to transport live fish over short distances for a short time in a state that the water has a relatively low weight equivalent to four times with respect to the weight of live fish.
However, in the conventional apparatus for cooling live fish, long refrigerant pipes are disposed as a zigzag passageway at the bottom surface or the side wall surface of the live fish tank or in the interior of the wet-type filtering tank. Furthermore, the evaporator may be installed in the live fish tank or the wet-type filtering tank. The drawback of the conventional apparatus for cooling live fish is that a long time occurs to install or repair the apparatus, and thereby resulting in increased costs.
Typically, the live fish tank may be formed by using the laminating strategy with FRP (Fiber Reinforced Polymer) materials. In order to manufacture the live fish tank, the first step of the laminating process is performed and then the process for installing the evaporator is performed. Thereafter, the process for connecting the refrigerant pipes between the constitutional elements for the live fish tank is performed. Then, the second step of the laminating process is performed. Then, it must perform repeatedly these steps several times and thereafter it is forced to finish working. To conclude, the conventional process for manufacturing the conventional live fish tank is quite complicated and difficult to perform.
In the course of installing the live fish tank in the live fish container, the process for disposing and fixing the evaporator at the bottom surface or the side wall surface of the live fish tank is quite difficult to perform. In the meantime, the evaporator may comprise relatively expensive titanium having the corrosion resistance. Since long refrigerant pipes are disposed as a zigzag passageway at the bottom surface or the side wall surface of the live fish tank or in the interior of the wet-type filtering tank, this leads to the dissipation of resources and to the increase of costs.
Meanwhile, when live fishes are loaded or unloaded in the course of transporting live fishes by using a trailer, they are likely to be damaged by the surface of the evaporator protruding toward the live fish tank due to the vibration or the shock to be applied to the live fish container. If the live fish receives a wound, it gets diseased and thereby value of commodities for the live fish deteriorates. Furthermore, since the surrounding temperature of the refrigerant tube for the evaporator is too lower than the temperature of live fish, the live fish is likely to get diseased or to die by getting stressed.
Meanwhile, there is a possibility that great quantities of scales are formed along the surface of the refrigerant pipe for the evaporator. This leads to the contamination of the live fish. Also, this leads to the decline of the heat exchanging effectiveness and the refrigerating performance. Therefore, it is difficult to reduce the temperature of live fish in the course of transporting live fish. As a result, it is hard to transport live fish over long distances for a long time in a state that the live fishes contained in the live fish container are maintained with ensuring the safety and the security thereof.
Meanwhile, in the conventional apparatus for cooling live fish, the refrigerant pipes extend up to the evaporator installed in the live fish tank of the driver unit. In order to prevent the refrigerant pipes from being corroded by live fish water, that is seawater, it must to perform a waterproof sealing process for refrigerant pipes by using specific lagging materials. This leads to increased costs in the manufacturing process of the apparatus for refrigerating live fish. Since there are many welded portions and connected portions between refrigerant pipes, the refrigerants are likely to be leaked there through due to the shock and the vibration applied to the live fish container during the process of loading or unloading live fishes or during the transportation of the live fish container by using a trailer. If the refrigerants are leaked through the welded portions and the connected portions between refrigerant pipes, live fishes may be died en masse. Since the welded portions and the connected portions between refrigerant pipes exist in great numbers, it is difficult to completely check the leakage of the refrigerants and it is hard to repair the damaged refrigerant pipes.
Meanwhile, the wet-type filtering tank installed in the live fish container generally includes filter media such as sand, gravel, non-woven fabric or sponge and so on by laminating them on a bottom of the live fish tank; and a filtering tank including filter media as such, which is installed at the outside of the live fish tank. The water may be filtered and purified by bacteria cultured in the filter media by making it flow through the filter media.
Furthermore, it was well that functional filling materials such as red clay or elvan (germanium) may be applied to the wet-type filter media so as to enhance the germicidal power and the sterilizing power of the wet-type filter media. Alternatively, some filling materials such as an activated carbon (charcoal) having an excellent adsorptive power can be applied to the wet-type filter media. Alternatively, some researchers attempt to illuminate ultraviolet rays to the live fish water in order to enhance the performance for purifying the live fish water.
Since a large number of live fishes are stored at high density in the live fish tank of the live fish container, it is difficult to effectively remove fine contaminants or protein components from the live fish water. Typically, a worker reduces the temperature of the live fish water so as to minimize the metabolism rate and the oxygen consuming rate. Since a variety of harmful ingredients resulted from live fish excrement, more particularly, ammoniac nitrogen components may be rapidly accumulated in the live fish at a high concentration, it is hard to effectively remove the harmful ingredients by only using the conventional wet-type filter media.
If the wet-type filter media is independently used in the live fish container, the filter media must be deposited in the live fish water or additional large filtering tank must be installed. In this case, the total weight of the live fish filtering tank including the filter media is too great, thereby resulting in the excessive weight of the live fish container. In other words, the excessive weight over the limit weights of 24 ton in the feet container or of 30 ton in the 40 feet container may be occurred, so that it is likely to break the rules with respect to the weight restrictions of live container.
In order to fulfill the rules with respect to the weight restrictions of live container, it is necessary to reduce the total size of live fish container including the filter media. This leads to the reduction in the quantity of live fish to be transported by using the live fish container at once. Accordingly, it is hard to reduce the logistical cost with respect to the transportation of live fish.
In the use of the conventional wet-type filter media, the live fish water may be circulated due to the operation of the circulation pump in a state that the filter media is immersed in the live fish water. As a result, the filtering efficiency is relatively low so that it is necessary to increase the volume occupied by the filter media so as to obtain a sufficient filtering capability. This leads to a remarkable reduction in the space for storing live fish.
As well known that, the ammoniac nitrogen components may be presented as two types of chemical formula such as NH3—N, NH4+—N which are combined with NH3 or NH4+, respectively. The ammoniac nitrogen components produced by combining with the nonionic ammonia can pass through a cell-wall of fish and can damage the live fish under even low concentration such as 2 mg/L or 2 ppm. Furthermore, the ammoniac nitrogen components may oxidize to the nitrate nitrogen or the nitrite nitrogen and they exhaust the dissolved oxygen in the water.
According to the rules of the U.S. Environmental Protection Agency, the content of the harmful ingredients such as ammoniac nitrogen must be removed below 0.002 mg/L so as to store the live fish with safe and fresh condition. However, it is impossible to remove these harmful ingredients by only using the wet-type filtering tank having a relatively poor filtering capability. If a transportation time of live fish by using a live fish container becomes long, the live fish is likely to be getting a certain disease due to the harmful ingredients accumulated in the live fish, thereby resulting in the death of live fish.
Consequently, the time limit for transporting live fish by using the conventional live fish container is only two days at maximum. Accordingly, the conventional live fish container is unsuitable for transportation live fish over a long distance for a long time and therefore it is only used for transportation over a short distance for a short time. As a result, a large number of live fish must be transported not on the sea and the land but on the air. This has resulted in high cost of transporting live fish and thereby it has poor productivity.
In the conventional live fish container, pumping means for circulating and purifying live fish water through the wet-type filter media are installed in the cargo room of the live fish container. Additionally, a live fish sterilizer, an oxygen supplying device and a lighting installation may be installed in the cargo room of the live fish container. Furthermore, a control part comprising a control panel, a battery and an inverter may be installed in the cargo room of the live fish container.
The control panel to be installed in the cargo room of the live fish container can function to control the operation of the live fish container together with the unit control box of the driver unit. The inverter can function to switch the electric power so as to allow the live fish container to be operated by receiving the electric power from the battery while an outer electric source is not applied to the live fish container.
If a worker uses the live fish container to be operated as described above, he or she must reduce the temperature of live fish water to a predetermined temperature at which the live fish goes to hibernation so as to survive live fishes during the transporting time period of live fish. Also, the worker makes the interior and the outside of the live fish container to be completely sealed so as to prevent the chill from being leaked.
If the moisture of the live fish water stored in the live fish water tank is accumulated in the cargo room, the internal air of the cargo room has a very high humidity. Since seawater is typically used as the live fish water, the salt concentration contained in the internal air of the cargo room and the moisture is also high.
One drawback of this conventional live fish container is that the control panel, the battery and the inverter of the control part are likely to be easily corroded or damaged due to the internal moisture of the cargo room and thereby resulting in the breakdown or the malfunction of the control part. Accordingly, there are many problems in the safe transportation of live fish by using the live fish container.
In order to solve the problem as described above, electronic control components, the battery and the inverter of the control panel must be inserted into the sealing-type case so as to prevent them from contacting with the internal air. Since it is difficult to effectively cool the heat to be generated during the operations of the electronic control components, the battery and the inverter, the breakdown or the multifunction may be occurred due to the overheating of the control part.
Since a person cannot enter into the cargo room during the transporting of the live fish in the live fish container, it is necessary to perform a manless operation for a long time. However, the control part installed in the cargo room is likely to be corroded or to be overheated so that it may be breakdown and a fire may be broken out. As a result, live fishes may be died en masse during the transportation of live fish. Furthermore, repair and maintenance costs for the control part are excessive.